3D printing concrete structures

A research team in Nanyang Technological University, Singapore (NTU Singapore), has managed to 3D-print concrete structures by the utilization of 2 robotic machines.

The project was developed by Pham Quang Cuong, Assistant Professor at NTU Singapore and his team. The innovation of 3D-printing concrete constructions lies on the automation of the procedure and the potential to create designs that are not feasible to achieve with conventional methods. Moreover, structures can be delivered quicker.

Until today, 3D-printing of large structures demands vast printers which are not convenient in construction industry due to space limitations. However, the utilization of mobile robots can alter the situation as they can operate around the construction site, making progress step-by-step. The robots at NTU managed to produce a 1.86m x 0.46m x 0.13m concrete structure in just 8 minutes. One week later, the sample had achieved its full strength and was ready for installation.

3D-printing using robotic technology is very challenging as robots have to operate individually not interacting with each other. Therefore, a robot has to be programmed as to conduct a specific task that is dependent on the other's robot occupation at the time. Moreover, the construction cannot be delayed or achieved in segments as the joints between parts will create a weakness plain. Researchers have developed a special algorithm that ensures the avoidance of these issues. Even mixing and pumping of the specialized liquid concrete mix are intricately designed to ensure coherence.

Professor Pham Quang Cuong expects that the team's research will soon be implemented in industry. "We envisioned a team of robots which can be transported to a work site, print large pieces of concrete structures and then move on to the next project once the parts have been printed," he said. In the future, the team will investigate the manipulation of more than 2 robots in order to achieve even larger concrete constructions.

According to Professor Chua Chee Kai, Executive Director of the Singapore Centre for 3D Printing, even more departments of construction industry (e.g. additive manufacturing) have the potential to expand and develop using robotics technology. "This multiple robot printing project is highly interdisciplinary, requiring roboticists to work with materials scientists to make printable concrete. To achieve the end result of a strong concrete structure, we had to combine their expertise with mechanical engineers and civil engineering experts. Such an innovation demonstrates to the industry what is feasible now, and prove what is possible in the future if we are creative in developing new technologies to augment conventional building and construction methods," he explains.